Answer:
Step-by-step explanation:
I'm not sure my way is going to be any quicker or better. Let's take an example.
Suppose you start with 456
Put a decimal at the end of the 6. You get 456.
Shift the decimal to the left one place 45.6
Divide by 2
22.8 (done mentally)
Note: dividing by 2 is easier than dividing by 5. Or multiplying by 5 for that matter.
Check the result.
456 * 5/100 =2280 / 100.
Shift a decimal 2 places to the left.
22.80 which agrees with your result.
Answer:
210.0
Step-by-step explanation:
you are rounding to the tens place so you look at the number before it is greater than 5 so you round up getting your answer of 210.0
Answer:
$356
Step-by-step explanation:
So if they are 400 students we need to:
0.89*400=$356
Answer: 
Step-by-step explanation:
We have given the numbers = 2,0,1,9
We can use addition and subtraction operation to the given numbers such that the answer will be equals to 6.
We can add 2 ,0 and 1 and then subtract from 9 , we will get 6.
So the required expression can be

hence, the required expression can be 
21 can go into 44 2 times